G0KTN Amateur Radio - 2026 current projects and technical notes

  Winter vs Summer on 40 Metres Why season often matters more than the solar cycle During the peak of Solar Cycle 25, many operators noticed something that at first seemed puzzling. Solar activity was high, higher HF bands were lively, and yet 40 metres often behaved very differently depending on the time of year. Winter sessions produced long runs of workable DX, while summer daytime operation could feel noisy and unrewarding despite excellent conditions elsewhere on the spectrum. This contrast is not an anomaly, nor a failure of the solar cycle to deliver on 40m. It reflects a basic reality of HF propagation: on 40 metres, seasonal effects often dominate behaviour more strongly than the solar cycle itself . Using CW Reverse Beacon spot data covering late 2024 through the whole of 2025, this article looks at how and why winter and summer produce such different 40m experiences, even under broadly similar solar conditions. What operators commonly notice Most experienced HF op...

  Solar Maximum and Lower-Band Absorption Why 40 metres does not simply improve at solar maximum Each solar maximum brings a familiar expectation among HF operators: if the Sun is more active, surely all bands should benefit. When 10 metres begins producing regular and sometimes spectacular openings, it is natural to assume that 40 metres will also improve in some obvious and sustained way. In practice, that expectation is often disappointed. Many operators find that daytime performance on 40m remains unchanged, or even feels worse, during periods of high solar activity. Using spot data sent to the Reverse Beacon Network (RBN) spanning late 2024 through 2025, this article looks at why that experience is not only common, but entirely consistent with how the ionosphere behaves near solar maximum. The simple intuition - and its limitation The intuitive picture most of us carry is straightforward: more solar activity produces more ionisation, more ionisation should improve...

  Following the MUF Up and Down the Bands What a Reverse Beacon Node heard during the peak of Solar Cycle 25 Most of us don’t experience propagation through charts or indices - we experience it through habits. We notice when 10 metres wakes up late in the morning, when 12 metres hangs on longer than expected, or when 40 metres starts to sound better as the higher bands go quiet. We may talk about MUF, but we usually recognise it through band behaviour rather than numbers. Between late August 2024 and December 2025, my Reverse Beacon node (which runs continuously 24/7/365) logged a vast number of CW spots across the HF amateur bands from 40m through to 10m. This period conveniently spans the recognised peak phase of Solar Cycle 25 and the months immediately after. Because the receive site remained unchanged (same location, same antenna, same general noise environment), the dataset provides a stable way to look at how MUF behaved day-to-day through solar maximum. What follows is...

  CQWW CW from a Back Garden: What a Wellbrook Loop Can Really Hear A technical reflection on 48 hours of contest-weekend propagation from IO81ti Every year, CQWW CW gives HF radio a proper stress test, with stations worldwide lighting up the bands with thousands of signals. For those that enjoy the propagation and technical side of the hobby, it’s also one of the best opportunities to observe how the ionosphere behaves under heavy and continuous loading. This year (2025) I decided to treat the contest as a propagation experiment. My Reverse Beacon Network (RBN) node, which normally runs continuously on all HF bands, was pointed at the six HF contest bands for the entire 48-hour period: 160, 80, 40, 20, 15 and 10. The receive antenna was not a tower-mounted Yagi or a phased Beverage farm… but a Wellbrook 1530LN magnetic loop mounted about 2m above ground in a typical UK suburban back garden (QRA IO81ti). The question was simple: what can a modest receive system really hear du...